Automatic telephonic installation.



B. KUGELMANN. AUTOMATIC TELEPHONIG INSTALLATION.

:APPLIOATION FILED SEPT. 15.1903,

, PATENTED MAR. 6, 1906.

UNITED STATES,

PATENT orrron BERNHARD KUGELMANN, OF B'AD KISSINGEN, G ]3ll%l\/IAJIY. AUTOMATIC TELEPHONIC INSTALLATHONB Patented March 6, 1906.

Application filed September 15, 1903. Serial No. 173.286.

' To (LZZ whom, it'may concern:

one conductor common to all.

Be it known that I, BERNHARD KUGEL MANN, a subject of'the King of Bavaria, 'residing at Bad Kissingen, Bavaria, Germany,

suitable appliance in the house of each subscriber he can deprive the lead of any bridge of current'if he introduces a suitable resistance in his line-wire to the central station. In the example described the bridges at the central-stationare arranged in two columns corresponding to units and tens for each four bridges, (in'correspondence with the ciphers Each subscriber has at the central station an auxiliary circuit, which aux.- iliary circuit contains in a s ecial switch arrangement electromagnetic devices for establishing telephonic connections. This auxiliary circuit is opened in each of the two columns at a bridgethe two bridges corresponding to the'two ciphers of the callingnu-mber of the subscriberand can be closed for a moment by any other subscriber by means of sensitive relays by a rapid succession of current intermissions in the leads of the said two bridges. As the selection d'e. vice (bridges) is common to all the subscribers, a device isne'cess ary to revent the .Sub-

scribcrs from disturbing eac 1 other in oper ating the selection device; 'On accountof that the arrangement is such that the calling subscriber after introducing the beforementioned resistances is not yet connected to the selecting device, but first sends acurrent into a waiting device at the central station. The connection with the selecting device is effected automatically by means of the waitin device by a current impulse sent to the ca ling subscriber in-such manner that only .one subscriber at a time is connected. The telephon c connection results by a current impulse caused by the calling subscriber,

WhIch current impulse selects at th 'central ing the auxiliary circuit of the calling sub scriber either by means of a relay at the central station or by earthing the line at the subscribers station, so the electromagnetical switch device of the calling subscriber, which is'in connection with the auxiliary circuit, is excited at this switch apparatus and connects, by means of its armature, the line-wire of the calling subscriber with the telephonewire. The called subscriber, however, will be connected to this telephone-wire, "as his auxiliary circuit is closed by the common selection device-in consequence of the momentary absence of current caused by the calling subscriber in the correspondin bridges and thus the electromagneticaj switch device of the called subscriber, which is in connection with the auxiliary circuit, will be excited at this switch apparatus. The telephonic connection of a subscriber is maintained by the current passing through his auxiliary circuitand'through a stop-relay and its armature, which prevents the subscriber from being called from another subscriber through the electromagnetical switch device and over the common electroma net and armature that are at the corresponding switch a paratus. If, for example, it be as sumed tiiat the installation in questionis to be sufficient for the simultaneous speaking of twelve subscribers, there will be required six switch apparatuses.

In the accompanying drawings. is shown a diagram of connections for two subscribers, the number of subscribers being sixteen with twice four bridges and one hundred with twice ten bridges. The insulation is indicated by thick black lines.

- Figure 1 shows the principle of the select mon to all subscribers, each subscriber being able to cdnnecthimself with such circuit by line-wire to the subscriber and V the variable resistance included at the subscribers station, the latter can produce absence of current in the bridge branch 9 if the combined resistance connected to the points d, e is In this the sources of current S of the other bridges are neglected. In case they are considered, h is'to be replaced by the expression k If R is sufficiently large, the subscriber must, as shown by the above formula, effect considerable alteration of V for producing a comparatively small change in the value of the above expression, which is a great advantage of this arrangement, as alterations of f have -no material influence. In consequence hereof the Thomson bridges are referable to other bridges, as they possess tfiemselves a high resistance and admit of a sufficiently large R. At each subscribers station there 's a switch resistance with two movable contacts; further, an electromagnetical device (electromagnet 24, armature 27) which is o erated from the waiting device at the centra station and causes the resistances V and V intercalated in order to put in function the common selective device, to be in rapid succession earthened through the contacts 39 and 40. This earth connection is produced by exciting the electromagnet 24,

' which attracts the armature 27 so that the 28, 20, and 31 being 1 tacts 11 and 12 upon the points of the switch resistance corresponding to bridge 4 of the first column and bridge 3 of the second column, and he then closes contact 13. The waiting device is assumed to be unoccupied. From the common source of current 14, whose negative pole is at 15, a current impulse passes through the connection-point 16, contact 17, rela 18, contact 19,armature 20, contact 21, line-wire 22, contacts 23 and 13, relay 24, armature 25, and through 26 to earth. This current is not sufliciently strong to attract the armatures and 27 On the other hand, armature is attracted and also armature 28. In that position the two armatures are kept attracted by the current from earth at the calling-subscribers station, current source 36, contact 35, armature 25, relay 24, contacts 13 and 23, line-wire 22, contact 21, armature 20, contact 19, relay 18, contact 34, earththe relays 24 and 18 remaining weakly energized. Armature 28 causes a current to ass from current source 14 through connection-point 16, contact 29, relay 30, and back to 14. In consequence hereof relay 3O attracts its armature 31 and effects a contact of short duration at 32, so that from the common strong current source 33,whose negative pole is connected to earth, a current impulse flows on the one hand through relay 18, contact 34, to earth and on the other hand through contact 19, armature 20. contact 21, line-wire 22, contacts 23 and 13, relay 24, contact 35, and current source 36 to earth.- (Armature 31 is only for a moment in connection with contact 32. When armature 31 is in its normal position or attracted by rela 30, contact 32 is 0 en.) The relays 18 and 24 in consequence of this strong current attract their armatures 20 and 27 so that the resistances included by the subscriber are connected consecutively and momentan'l through contact 37, common lead 38 with the bridges, and through contact 39 or 40 with the return-lead of the bridgesthat is, in the present caseto earth. Although contact 32 is only closed for a moment, and-consequently the heavy current flows over the relays 18 and 24 for only a very short time, the armature 20 will, neverthe-- less, owing to a certain inertia, keep the contacts 37 60 closed until the following connecting operations have taken place. The same is true of the armature 27 which interrupts its own circuit, but under the influence of the current impulse completely carries out its movement, which is necessary in order to bring contact 39 and immediately following contact 40 in contact with conductor 26. The mechanical construction therefor may be the same as the usual construction for relay-armatures. The schematic view deviates from this latter construction in which the relay-armatures are source 14 andby means of their armatures 28 haven the same time effected contact at 29 will consecutively'receive the return impulses for effecting the necessary connections,

inasmuch as only the relay 30 of a subscriber contact 41 until the armature 28 of the said and bridge 3'of the second column.

15 raril closed and contact 23 is interrupted by t e im ulse, so that jarmature-28 at once assumes t e osition of rest. selection device by which the auxiliary currents are closed consists of two columns of bridges. The drawing shows eight bridges in two columns. The brid es are connected 'by the points 0 c with con uctors 38 by the points d d with the earth. The auxiliary circuit of the desired subscriber 43 is closed by the relay of the bridge 4 of the first column and the bridge 3 of the second column. 'If there are auxiliary circuits, the call-numbers of which are to contain 0 for instance, 400r numbers less than tenfor, in-

stance, call-number "07 and othersthen every column must receive a bridge with the number 0. The connection of the subscribers station A to the bridges produces in consequence of what has been said above for-a moment absence of current consecutively in the bridge-leads of the bridge 4 of the};1 first T e relays in the bridge-leads consequently let their armatures drop and close the contacts 42 43 and rapidly succeeding 44 45. In conse- (1111181108 hereof a current impulse flows from t e common current source 46 (whose negative pole is earthed) to the switch apparatuses. The drawing shows two switch appae ratuses I and II. At every switch apparatus there' is attributed to every subscriber in connection with his auxiliary circuit an electromagnetical switch device, (electroma net '55 which in operating connects the inewire 81 81 of the subscriber to a common telephonic line 83 through a contact, 82 82. There is further a common electro- "magnet 51, provided at every switch apparatus, serving by means of its. armature 71 the current impulse effecting the connection -t0'this switch apparatus or, if it is occupied, to offer the way to the nearest" other one.

switch apparatus through the electromaget 55) of ithe calling subscriber, (because t 's electro- -niagnet has on the one hand earth connection .overconnection-point 56, armature 57, relay 5 58, contact 21, line 22, contacts 12 40, con- The common the conductor 38 to'earth.) magnet 51 is energized and attracts arma and the contacts 52 and 72 to'offer a way to.

ductor 26,'earth, on the other hand over con tact 60, line 38-, and over the bridges at the central station. For, as mentioned above, contact 60 remains closed for a moment owin For t e same reason as mentioned above the contact 40 is also closed until the following circuits are closed, which lasts for only a fractional part of a second,) and also through the electromagnetical switch device (e1'ectromagnet 55) of the called subscriber, because this is earthened by means of the selection device throu h contact 44 42. If it be assumed that t e first switch apparatus is unoccupied, then in the present example the current impulse flows on the one hand through 47, connection-point,-.contacts 48, 43, and 4,5, to the common lead 49 and through contact 50, relay'51, contacts 52 and 53, armature 54, electromagnet 55, connection-point 56, armature 57, relay 58, conductor 59, contacts 44 42 to earth. As at this moment, as just before mentioned, the auxiliary circuit of the calling subscriber is also connected to earth at contact 60, the current impulse branches from contact 52 through the switch-electromagnet 55 of the caller-namely, through contact 53, armature 54, electroma net 55, connection-point 56, armature 57, re ay 58, contacts 60 21,line wire 22, contacts 12 40, conductor 26 to earth (A current whose intensity is dependent upon the resistance of the bridges passes throi'igh The electroture 71, so that this switch apparatus is engagged and is bridged over at 72 for current impulses of other subscribers. Furthermore, the swrtch-electroniagnets 55 and 55 of the two subscribers are excited and attract their I 46 through connection-point 47, contact 74,

relay 58, armature 57, connection-point 56,

to a certain inertia of the armature 20.

electromagnet 55, armature 54, contact 75,

comrnonlead 76,contact 77, relay 51, contact 1 78, conductor 79 to 46. in a corresponding manner the current for the calling subscriber flows through 47, 74, 58, 57, 56, 5.3, 54, 75,

76, 77, 51, 78, 79, 46. VVhon the calling subscriber takes his receiver '1 oil the hook,

a current flows from currclitsourvo 36 through the speaking circuit-contact 80, line-wire 81,- armature 54, contact 82, common speaking-wire 83, through 82 81, audible signal K of the called subscriber to earth. This current also branches from 81 through relay 84 to earth, so that the suspended swinging armature 85 is attracted. This armature 85 is soarranged that in the normal condition the contact at spring 57 from armature becomes currentless, (by replacing the receiver of the subscriber,) armature 85, which is hung freely movable, returns to position of rest, swings hereby beyond this position of rest and opensfor a moment the contact at 57. The same is true of armature 85 of the called-up subscriber. After the speaking is finished this armature in swinging back interrupts contact 57 and IQStLbliSllBS the position of rest of the influenced circuits. Armature 85 acts in the same way.

Having thus particularlydescribed and ascertained the nature of my said invention and the best means'I know of carrying the same into practical effect, I claim- 1. In an automatic telephone system, the combination with the lines of the subscribers, of a number of switch apparatuses, each including one common speaking-way and aseries of relay devices, one of such devices in eachseries being attached to each subscribers line for control by the subscriber, each relay device adapted to join the corresponding line of the subscriber to the said common speakingway, and each apparatus when occupied bringing the next unoccupied switch apparatus into the sphere of control of the subscribers.

2. In an automatic telephone-exchange system the combination with. the lines of the subscribers, of a number of switch apparatuses, each including a series of relay devices, auxiliary circuits, acommonselectin device at the central station, comprising a Iurality of Thomson bridges divided into coiiimns of a certain number of bridges, the several colunms representing respectively units and tens of the numbers of subscribers, the auxiliary circuit .of a subscriber being closed by the relays of those bridges, which correspond to the call-number of this subscriber.

subscribers, of a number of switch apparatuses, each including a series of relay devices, of a selecting device, relay arrangements at the central station, a relay arrangement 24 at the substation for each subscriber, contact devices 2.) on the central station, contact devices 41 on the central station, a circuitfor each subscriber over all said contact devices, 41, being adapted to close the said contact device 29 of the subscriber, a circuit for each subscriber over a number of the said contact devices 41 and over the contact device 29 of the subscriber, being adapted by energizing the said relay arrangements to connect simultaneously calling subscribers successively with the said selecting device.

4. In an automatic telephone-exchange system the combination with the lines of the subscribers, of a number of switch apparatuses, each including a series of relay devices, auxiliary circuits, a selecting device, a common lead 49,.a current source 46, an electromagnet 51 for each switch apparatus an armature of this electromagnet 51, a contact 52 for each switch apparatus, over which the said current source 46 and the said switch apparatus are in connection during the position of-rest of the said armature 71, a contact 72 for each switch apparatus over which the said current source 46 is in connection with the next unoccu ied switch apparatus during the actuation o the said armature 71, contacts 77 and 78 for each switch apparatus over which the said current source 46 is in connection with the energized relays of the said switch apparatus during the actuation of the said armature 71, relays 58, 58 for each of the said auxiliary circuitsadapted to separate its auxiliary circuit from the said selectin device on actuation.

n witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

G. BARDEL E. BARDEL. 

